Diana Through intensive research, spurred on by atDNA testing and helped by collaboration with my atMatches, I've determined my parents were 8th cousins! They never knew it. From their common ancestor, Sion W HILL 1654-1705 VA, their respective lines of descent followed very different paths through VA until their marriage. When I learned this, it explained (to me) why I was finding identical atDNA segments in atMatches with paper trails on both sides. I have since learned that most of these small segments are IBS flotsam and jetsam. In looking at my tree, I know all my ancestors out to 16/16. Then it's 28/32, 48/64, 73/128, 108/256, 160/512, 192/1024, and 236/2048 (roughly 10 percent). The point is that there is a high percentage of unknown ancestors, where an atDNA Common Ancestor could be hiding - including those that would make you your own cousin. Do the math at your 6th cousin level (# known ancestors/128) and subtract from 1 (even an EE can do it) - this will give you a sense of what you don't know about your ancestry. I picked 6th cousin level, because cousins at that level would look like 4th or 5th. Jim - Sent from my iPhone - FaceTime! On Feb 15, 2012, at 2:58 AM, "Diana Gale Matthiesen" <[email protected]> wrote: > I just noticed something that has me perplexed. I have now FF tested > three cousins on my father's side of the family and one on my mother's > side. I just noticed that that there are two people in common with > the me and with a cousin on each side of my family. What has me > perplexed is that there is nothing in my parents' paper genealogies to > even suggest they have any recent ancestors in common. > > The relationships suggested here are 3rd and 4th cousin to 4th-remote > and 5th-remote. What is the probability that someone matching at > these levels is *not* actually related in genealogical time? And what > is the probability of two people matching the same two people at these > levels and still not be related? > > Diana
Some years ago, I compiled a table of the number of individuals in each generation of your ancestry: http://dgmweb.net/Ancillary/OnE/NumberAncestors.html That was when I set my genealogical goal at getting all my lines back ten generations. It's almost ridiculous to be proud of an ancestor 20 or 30 generations back. At best, they've contributed a miniscule amount to your genetic endowment - possibly even none. Nothing's impossible, but I'm going to be very surprised to find my parents related within the reach of the FamilyFinder test. If these mutual matches I'm getting from both sides of my family are IBS, that's solves that problem, but then that raises the question as to whether I should have accepted the DAVIS in this table as our cousin: http://dgmweb.net/DNA/aDNA/FF-Descendants_Isaac_DAVIS.html#table Diana > -----Original Message----- > From: [email protected] [mailto:autosomal-dna- > [email protected]] On Behalf Of Jim Bartlett > Sent: Wednesday, February 15, 2012 8:10 AM > To: [email protected] > Subject: Re: [AUTOSOMAL-DNA] when is a match not a match? > > Diana > > Through intensive research, spurred on by atDNA testing and helped > by collaboration with my atMatches, I've determined my parents were > 8th cousins! They never knew it. From their common ancestor, Sion W > HILL 1654-1705 VA, their respective lines of descent followed very > different paths through VA until their marriage. > > When I learned this, it explained (to me) why I was finding > identical atDNA segments in atMatches with paper trails on both > sides. I have since learned that most of these small segments are > IBS flotsam and jetsam. > > In looking at my tree, I know all my ancestors out to 16/16. Then > it's 28/32, 48/64, 73/128, 108/256, 160/512, 192/1024, and 236/2048 > (roughly 10 percent). The point is that there is a high percentage > of unknown ancestors, where an atDNA Common Ancestor could be hiding > - including those that would make you your own cousin. > > Do the math at your 6th cousin level (# known ancestors/128) and > subtract from 1 (even an EE can do it) - this will give you a sense > of what you don't know about your ancestry. I picked 6th cousin > level, because cousins at that level would look like 4th or 5th. > > Jim - Sent from my iPhone - FaceTime! > > On Feb 15, 2012, at 2:58 AM, "Diana Gale Matthiesen" > <[email protected]> wrote: > > > I just noticed something that has me perplexed. I have now FF > tested > > three cousins on my father's side of the family and one on my > mother's > > side. I just noticed that that there are two people in common > with > > the me and with a cousin on each side of my family. What has me > > perplexed is that there is nothing in my parents' paper > genealogies to > > even suggest they have any recent ancestors in common. > > > > The relationships suggested here are 3rd and 4th cousin to 4th- > remote > > and 5th-remote. What is the probability that someone matching at > > these levels is *not* actually related in genealogical time? And > what > > is the probability of two people matching the same two people at > these > > levels and still not be related? > > > > Diana > > > > ______________________________ > For answers to Frequently Asked Questions about mailing lists, > please see: > http://dgmweb.net/MailingListFAQs.html > > > ------------------------------- > To unsubscribe from the list, please send an email to AUTOSOMAL-DNA- > [email protected] with the word 'unsubscribe' without the quotes > in the subject and the body of the message